PHPExcel Freezepane not working

You might be exceeding the 65,000 limit, what do you set the $rowscounter initial value at? 1 or 0 (zero)? The reason I ask it that the array results starts at index 0 (zero), you're adding the row and then incrementing the counter after the add. So if you start the counter at 0 (zero) than you might have more rows that what you have counted. Also you are missing a row in the else statement, you loop through a value but don't add it to the sheet

try this

$rowscounter = 1;

foreach($result as $value)
{
    $val = array_values($value);

    if($rowscounter < 65000)
    {
        $objPHPExcel->addRow($val,$rowscounter);
    }
    else
    {
        $active_sheet++;
        $objPHPExcel->createSheet();
        $objPHPExcel->setActiveSheetIndex($active_sheet);
        $rowscounter = 1;

        // add missing row
        $objPHPExcel->addRow($val,$rowscounter);
    }
    $rowscounter++;
}
// deliver header   
header("Content-Type: $mtype; charset=" . $objPHPExcel->sEncoding);
header("Content-Type:application/octet-stream");
header("Content-Disposition: inline; filename=\"" . $filename . ".$ext\"");

// Save it as an excel 2003 file
$objWriter = IOFactory::createWriter($objPHPExcel,$objPHPExcel->sFileFormat);
//echo "Peak memory usage: " . (memory_get_peak_usage(true) / 1024 / 1024) . " MB";exit;
$objWriter->save('php://output');

a simple example of what I'm trying to explain, if $i is set to 0 (zero) the else condition is not met. So you will have an extra row in your results. If $i is set to 1 the else condition is met

$count = array(1,2,3,4,5,6,7,8,9,10);
$i=1; // set this to 0 (zero) and test, set to 1 and test

foreach($count as $cnt) {
    if($i < 10) {
        echo "If condition - Count value: ".$cnt." i value:".$i."<br />";
    } else {
        echo "Else condition - Count value: ".$cnt." i value:".$i."<br />";
    }
    $i++;
}

This is complete solution use header('Pragma: ');